UNITED
STATES




SECURITIES
AND EXCHANGE COMMISSION




WASHINGTON,
D.C. 20549




FORM
10-Q




[X]
            QUARTERLY
      REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF
      1934




For the
quarterly period ended June 30,
2009




OR




[  ]
            TRANSITION
      REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF
      1934




For the
transition period from  to




Commission
File number:    000-53043




Man-AHL Diversified I L.P.





(Exact
name of registrant as specified in charter)




Delaware
                    
                    06-1496634(State
      or other jurisdiction of incorporation or organization)
                    
                    (IRS
      Employer Identification
No.)







c/o
      Man Investments (USA) Corp.123
      North Wacker Drive28th
      FloorChicago, Illinois
                      
                      60606(Address
      of principal executive offices)
                      
                      (Zip
      Code)





(312)
881-6800


(Registrant’s
telephone number, including area code)




Indicate
by check mark whether the registrant (1) has filed all reports required to be
filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the
preceding 12 months (or for such shorter period that the registrant was required
to file such reports), and (2) has been subject to such filing requirements for
the past 90 days.


Yes
[X]    No [  ]





Indicate
by check mark whether the registrant has submitted electronically and posted on
its corporate Web site, if any, every Interactive Data File required to be
submitted and posted pursuant to Rule 405 of Regulation S-T (§232.405 of this
chapter) during the preceding 12 months (or for such shorter period that the
registrant was required to submit and post such files).


Yes
[  ]    No [  ]





Indicate
by check mark whether the registrant is a large accelerated filer, an
accelerated filer, a non-accelerated filer or a smaller reporting
company.  See the definitions of “large accelerated filer,”
“accelerated filer” and “smaller reporting company” in Rule 12b-2 of the
Exchange Act.




Large
      Accelerated Filer [  ]
                
                Accelerated
      Filer   [  ]Non-Accelerated
      Filer   [  ]
                
                Smaller
      reporting
company  [X]




Indicate
by check mark whether the registrant is a shell company (as defined in Rule
12b-2 of the Exchange Act).




Yes
[  ]    No [X]







PART I - FINANCIAL
INFORMATION








ITEM
1.                      Financial
Statements.




Man-AHL
Diversified I L.P.


Financial
Statements





STATEMENTS
OF FINANCIAL CONDITION (a)


STATEMENTS
OF OPERATIONS (b)


STATEMENTS
OF CHANGES IN PARTNERS’ CAPITAL (c)


STATEMENTS
OF CASH FLOWS (c)


NOTES TO
THE FINANCIAL STATEMENTS (UNAUDITED)





(a)
            At
      June 30, 2009 (unaudited) and December 31,
2008


(b)
            For
      the three months ended June 30, 2009 and 2008 (unaudited) and for the six
      months ended


June 30,
2009 and 2008 (unaudited)


(c)
            For
      the six months ended June 30, 2009 and 2008
  (unaudited)





2


MAN-AHL
      DIVERSIFIED I L.P.(A
      Delaware Limited Partnership)STATEMENTS
      OF FINANCIAL CONDITIONJune
      30, 2009(unaudited)
                      
                      
                      December 31, 2008ASSETSCASH
      AND CASH EQUIVALENTS
                      
                      $
                      30,621,892
                      
                      
                      $
                      8,729,540INVESTMENT
      IN MAN-AHL DIVERSIFIEDTRADING
      COMPANY L.P.
                      
                      
                      270,592,247
                      
                      
                      
                      219,241,465DUE
      FROM MAN-AHL DIVERSIFIEDTRADING
      COMPANY L.P.
                      
                      
                      9,628,580
                      
                      
                      
                      7,575,576OTHER
      ASSETS
                      
                      
                      295
                      
                      
                      
                      295TOTAL
                      
                      $
                      310,843,014
                      
                      
                      $
                      235,546,876LIABILITIES
      AND PARTNERS’ CAPITALLIABILITIES:Redemptions
      payable
                      
                      $
                      8,489,102
                      
                      
                      $
                      4,516,740Subscriptions
      received in advance
                      
                      
                      30,621,892
                      
                      
                      
                      8,729,540Management
      fees payable
                      
                      
                      694,976
                      
                      
                      
                      566,720Incentive
      fees payable
                      
                      
                      -
                      
                      
                      
                      2,079,483Servicing
      fees payable
                      
                      
                      348,854
                      
                      
                      
                      283,360Accrued
      expenses
                      
                      
                      95,649
                      
                      
                      
                      129,273Total
      liabilities
                      
                      
                      40,250,473
                      
                      
                      
                      16,305,116PARTNERS’
      CAPITAL:General
      Partner - Class A (186 unit equivalents outstandingat
      June 30, 2009 and December 31, 2008, respectively)
                      
                      
                      589,217
                      
                      
                      
                      683,098Limited
      Partners - Class A (69,759 and 51,957 units outstandingat
      June 30, 2009 and December 31, 2008, respectively)
                      
                      
                      220,540,159
                      
                      
                      
                      190,432,028Limited
      Partners - Class A Series 2 (1,438 and 0 units outstandingat
      June 30, 2009 and December 31, 2008, respectively)
                      
                      
                      4,560,220
                      
                      
                      
                      -Limited
      Partners - Class B (13,593 and 7,674 units outstandingat
      June 30, 2009 and December 31, 2008, respectively)
                      
                      
                      42,975,013
                      
                      
                      
                      28,126,634Limited
      Partners - Class B Series 2 (608 and 0 units outstandingat
      June 30, 2009 and December 31, 2008, respectively)
                      
                      
                      1,927,932
                      
                      
                      
                      -Total
      partners’ capital
                      
                      
                      270,592,541
                      
                      
                      
                      219,241,760TOTAL
                      
                      $
                      310,843,014
                      
                      
                      $
                      235,546,876
  3
  MAN-AHL
      DIVERSIFIED I L.P.(A
      Delaware Limited Partnership)STATEMENTS
      OF FINANCIAL CONDITION (CONTINUED)NET
      ASSET VALUE PER OUTSTANDING UNIT OFPARTNERSHIP
      INTEREST - CLASS A
                    
                    $
                    3,161.48
                    
                    
                    $
                    3,665.21NET
      ASSET VALUE PER OUTSTANDING UNIT OFPARTNERSHIP
      INTEREST - CLASS A Series 2
                    
                    $
                    3,171.45
                    
                    
                    $
                    -NET
      ASSET VALUE PER OUTSTANDING UNIT OFPARTNERSHIP
      INTEREST - CLASS B
                    
                    $
                    3,161.49
                    
                    
                    $
                    3,665.22NET
      ASSET VALUE PER OUTSTANDING UNIT OFPARTNERSHIP
      INTEREST - CLASS B Series 2
                    
                    $
                    3,171.46
                    
                    
                    $
                    -See
      accompanying notes and attached financial statementsof
      Man-AHL Diversified Trading Company L.P.








4





MAN-AHL
      DIVERSIFIED I L.P.(A
      Delaware Limited Partnership)STATEMENTS
      OF OPERATIONS (UNAUDITED)For
      the three
                        
                        
                        For
      the three
                        
                        
                        For
      the six
                        
                        
                        For
      the sixmonths
      ended
                        
                        
                        months
      ended
                        
                        
                        months
      ended
                        
                        
                        months
      endedJune 30, 2009
                        
                        
                        June 30, 2008
                        
                        
                        June 30, 2009
                        
                        
                        June 30, 2008NET
      INVESTMENT INCOMEALLOCATED
      FROM MAN-AHLDIVERSIFIED
      TRADING COMPANY L.P. -Interest
      income
                        
                        $
                        98,540
                        
                        
                        $
                        574,809
                        
                        
                        $
                        230,367
                        
                        
                        $
                        1,088,781PARTNERSHIP
      EXPENSES:Brokerage
      commissions
                        
                        
                        163,458
                        
                        
                        
                        228,214
                        
                        
                        
                        290,623
                        
                        
                        
                        624,814Management
      fees
                        
                        
                        1,976,382
                        
                        
                        
                        820,725
                        
                        
                        
                        3,714,397
                        
                        
                        
                        1,416,838Incentive
      fees
                        
                        
                        -
                        
                        
                        
                        943,253
                        
                        
                        
                        -
                        
                        
                        
                        -Servicing
      Fees
                        
                        
                        990,802
                        
                        
                        
                        -
                        
                        
                        
                        1,859,809
                        
                        
                        
                        3,211,277Other
      expenses
                        
                        
                        99,333
                        
                        
                        
                        90,382
                        
                        
                        
                        270,287
                        
                        
                        
                        124,695Total
      expenses
                        
                        
                        3,229,975
                        
                        
                        
                        2,082,574
                        
                        
                        
                        6,135,116
                        
                        
                        
                        5,377,624Net
      investment loss
                        
                        
                        (3,131,435
                        )
                        
                        
                        (1,507,765
                        )
                        
                        
                        (5,904,749
                        )
                        
                        
                        (4,288,843
                        )REALIZED
      AND UNREALIZED GAINS(LOSSES)
      ON TRADING ACTIVITIESALLOCATED
      FROM MAN-AHLDIVERSIFIED
      TRADING COMPANY L.P.:Net
      realized trading gains (losses)on
      closed contracts
                        
                        
                        (17,782,871
                        )
                        
                        
                        5,447,631
                        
                        
                        
                        (23,200,497
                        )
                        
                        
                        18,726,225Net
      change in unrealized trading gains (losses)on
      open contracts
                        
                        
                        1,826,358
                        
                        
                        
                        (166,855
                        )
                        
                        
                        (8,410,914
                        )
                        
                        
                        (1,566,779
                        )Net
      gains (losses) on trading activities allocatedfrom
      Man-AHL DiversifiedTrading
      Company L.P.
                        
                        
                        (15,956,513
                        )
                        
                        
                        5,280,776
                        
                        
                        
                        (31,611,411
                        )
                        
                        
                        17,159,446NET
      INCOME (LOSS)
                        
                        $
                        (19,087,948
                        )
                        
                        $
                        3,773,011
                        
                        
                        $
                        (37,516,160
                        )
                        
                        $
                        12,870,603NET
      INCOME (LOSS) PER UNIT OFPARTNERSHIP
      INTEREST - CLASS A
                        
                        $
                        (231.15
                        )
                        
                        $
                        109.50
                        
                        
                        $
                        (503.73
                        )
                        
                        $
                        496.98NET
      INCOME (LOSS) PER UNIT OFPARTNERSHIP
      INTEREST - CLASS A Series 2
                        
                        $
                        (221.18
                        )
                        
                        $
                        -
                        
                        
                        $
                        (221.18
                        )
                        
                        $
                        -NET
      INCOME (LOSS) PER UNIT OFPARTNERSHIP
      INTEREST - CLASS B
                        
                        $
                        (231.15
                        )
                        
                        $
                        -
                        
                        
                        $
                        (503.73
                        )
                        
                        $
                        -NET
      LOSS PER UNIT OFPARTNERSHIP
      INTEREST - CLASS B Series 2
                        
                        $
                        (221.18
                        )
                        
                        $
                        -
                        
                        
                        $
                        (221.18
                        )
                        
                        $
                        -See
      accompanying notes and attached financial statementsof
      Man-AHL Diversified Trading Company L.P.





5





MAN-AHL
      DIVERSIFIED I L.P.(A
      Delaware Limited Partnership)STATEMENTS
      OF CHANGES IN PARTNERS’ CAPITAL (UNAUDITED)FOR
      THE SIX MONTHS ENDED JUNE 30, 2009 AND 2008CLASS
      A
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      CLASS
      A Series 2
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      CLASS
      B
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      CLASS
      B Series 2
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      TOTALLimited
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      General
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      Limited
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      Limited
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      LimitedPartners
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      Partner
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      Partners
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      Partners
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      PartnersAmount
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      Units
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      Amount
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      Units
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      Amount
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      Units
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      Amount
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      Units
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      Amount
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      Units
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      Amount
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      UnitsPARTNERS’
      CAPITALDecember
      31, 2007
                                                                                                                                                                      
                                                                                                                                                                      $
                                                                                                                                                                      59,016,037
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      20,393
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      $
                                                                                                                                                                      539,353
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      186
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      $
                                                                                                                                                                      -
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      -
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      $
                                                                                                                                                                      -
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      -
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      $
                                                                                                                                                                      -
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      -
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      $
                                                                                                                                                                      59,555,390
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      20,579Subscriptions
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      56,130,636
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      17,429
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      -
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      -
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      -
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      -
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      -
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      -
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      -
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      -
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      56,130,636
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      17,429Redemptions
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      (7,651,461
                                                                                                                                                                      )
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      (2,353
                                                                                                                                                                      )
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      -
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      -
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      -
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      -
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      -
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      -
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      -
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      -
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      (7,651,461
                                                                                                                                                                      )
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      (2,353
                                                                                                                                                                      )Net
      income
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      12,777,980
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      -
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      92,623
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      -
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      -
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      -
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      -
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      -
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      -
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      -
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      12,870,603
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      -PARTNERS’
      CAPITALJune
      30, 2008
                                                                                                                                                                      
                                                                                                                                                                      $
                                                                                                                                                                      120,273,192
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      35,469
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      $
                                                                                                                                                                      631,976
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      186
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      $
                                                                                                                                                                      -
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      -
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      $
                                                                                                                                                                      -
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      -
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      $
                                                                                                                                                                      -
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      -
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      $
                                                                                                                                                                      120,905,168
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      35,655PARTNERS’
      CAPITALDecember
      31, 2008
                                                                                                                                                                      
                                                                                                                                                                      $
                                                                                                                                                                      190,432,028
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      51,957
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      $
                                                                                                                                                                      683,098
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      186
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      $
                                                                                                                                                                      -
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      -
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      $
                                                                                                                                                                      28,126,634
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      7,674
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      $
                                                                                                                                                                      -
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      -
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      $
                                                                                                                                                                      219,241,760
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      59,817Subscriptions
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      87,597,562
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      25,511
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      -
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      -
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      4,757,000
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      1,438
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      23,633,887
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      6,906
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      2,090,000
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      624
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      118,078,449
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      34,479Redemptions
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      (25,769,506
                                                                                                                                                                      )
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      (7,709
                                                                                                                                                                      )
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      -
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      -
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      -
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      -
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      (3,391,737
                                                                                                                                                                      )
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      (987
                                                                                                                                                                      )
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      (50,265
                                                                                                                                                                      )
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      (16
                                                                                                                                                                      )
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      (29,211,508
                                                                                                                                                                      )
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      (8,712
                                                                                                                                                                      )Net
      loss
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      (31,719,925
                                                                                                                                                                      )
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      -
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      (93,881
                                                                                                                                                                      )
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      -
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      (196,780
                                                                                                                                                                      )
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      -
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      (5,393,771
                                                                                                                                                                      )
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      -
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      (111,803
                                                                                                                                                                      )
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      -
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      (37,516,160
                                                                                                                                                                      )
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      -PARTNERS’
      CAPITALJune
      30, 2009
                                                                                                                                                                      
                                                                                                                                                                      $
                                                                                                                                                                      220,540,159
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      69,759
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      $
                                                                                                                                                                      589,217
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      186
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      $
                                                                                                                                                                      4,560,220
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      1,438
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      $
                                                                                                                                                                      42,975,013
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      13,593
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      $
                                                                                                                                                                      1,927,932
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      608
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      $
                                                                                                                                                                      270,592,541
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      
                                                                                                                                                                      85,584See
      accompanying notes and attached financial statementsof
      Man-AHL Diversified Trading Company L.P.


6




MAN-AHL
      DIVERSIFIED I L.P.(A
      Delaware Limited Partnership)STATEMENTS
      OF CASH FLOWS (UNAUDITED)For
      the six
                
                
                For
      the sixmonths
      ended
                
                
                months
      endedJune 30, 2009
                
                
                June 30, 2008CASH
      FLOWS FROM OPERATINGACTIVITIES:Net
      income (loss)
                
                $
                (37,516,160
                )
                
                $
                12,870,603Adjustments
      to reconcile net income (loss)to
      net cash used in operating activities:Purchases
      of investment in Man-AHLDiversified
      Trading Company L.P.
                
                
                (118,078,449
                )
                
                
                (53,710,438
                )Sales
      of investment in Man-AHLDiversified
      Trading Company L.P.
                
                
                33,293,619
                
                
                
                8,835,070Net
      change in appreciation (depreciation)of
      investment in Man-AHLDiversified
      Trading Company L.P.
                
                
                31,381,044
                
                
                
                (18,248,227
                )Changes
      in assets and liabilities:Other
      assets
                
                
                -
                
                
                
                476Management
      fees payable
                
                
                128,256
                
                
                
                157,878Incentive
      fees payable
                
                
                (2,079,483
                )
                
                
                434,529Servicing
      fees payable
                
                
                65,494
                
                
                
                -Brokerage
      commissions payable
                
                
                -
                
                
                
                (46,834
                )Accrued
      expenses
                
                
                (33,624
                )
                
                
                18,453Net
      cash used in operating activities
                
                
                (92,839,303
                )
                
                
                (49,688,490
                )CASH
      FLOWS FROM FINANCINGACTIVITIES:Proceeds
      from subscriptions
                
                
                139,970,801
                
                
                
                74,609,969Payments
      on redemptions
                
                
                (25,239,146
                )
                
                
                (4,021,948
                )Net
      cash provided by financing activities
                
                
                114,731,655
                
                
                
                70,588,021NET
      INCREASE IN CASH
                
                
                21,892,352
                
                
                
                20,899,531CASH
      AND CASH EQUIVALENTSBeginning
      of Period
                
                
                8,729,540
                
                
                
                4,225,671CASH
      AND CASH EQUIVALENTSEnd
      of Period
                
                $
                30,621,892
                
                
                $
                25,125,202SUPLEMENTAL
      DISCLOSURE OFNON-CASH
      TRANSACTIONS:Non-cash
      contributions of partners' capital
                
                $
                -
                
                
                $
                2,420,198Non-cash
      redemptions of partners' capital
                
                $
                -
                
                
                $
                (2,420,198
                )See
      accompanying notes and attached financialstatements
      of Man-AHL Diversified Trading Company L.P.








7


Notes
to Financial Statements (unaudited)





The
accompanying unaudited financial statements, in the opinion of management,
include all adjustments (consisting only of normal recurring adjustments)
necessary for a fair presentation of Man-AHL Diversified I L.P.’s (a Delaware
Limited Partnership) (the “Partnership”) financial condition at June 30, 2009
and the results of its operations for the three months ended June 30, 2009 and
2008 and six months ended June 30, 2009 and 2008.  These financial
statements present the results of interim periods and do not include all the
disclosures normally provided in annual financial statements.  It is
suggested that these financial statements be read in conjunction with the
audited financial statements and notes included in the Partnership’s annual
report on Form 10-K filed with the Securities and Exchange Commission on March
31, 2009.  The December 31, 2008 information has been derived from the
audited financial statements as of December 31, 2008.







1.
            ORGANIZATION
      OF THE PARTNERSHIP




Man-AHL
Diversified I L.P. (a Delaware Limited Partnership) (the “Partnership”) was
organized in September 1997 under the Delaware Revised Uniform Limited
Partnership Act and commenced operations on April 3, 1998, for the purpose of
engaging in the speculative trading of futures and forward contracts. The
Partnership is a “feeder” fund in a “master-feeder” structure, whereby the
Partnership invests substantially all of its assets in Man-AHL Diversified
Trading Company L.P. (the “Trading Company”). Man-AHL (USA) Corp., a Delaware
corporation, was the general partner and trading advisor of the Partnership and
the Trading Company until April 1, 2005, when it transferred its trading
advisory business to its affiliate, Man-AHL (USA) Ltd. (the “Advisor”), a United
Kingdom company, and its commodity pool operations to its affiliate, Man
Investments (USA) Corp. (the “General Partner”), a Delaware corporation and a
registered investment adviser under the Investment Advisers Act of 1940. Man
Investments Holdings Limited, a United Kingdom holding company that is part of
Man Group plc, a United Kingdom public limited company, is the sole shareholder
of the Advisor, and Man Investments Holdings Inc., a Delaware corporation that
is part of Man Group plc, is the sole shareholder of the General
Partner.




Effective
July 1, 2008, the Partnership issued a new class of units, Class
B.  Class B was created solely for retirement plan investors. The fee
structure is identical to Class A.




The
Partnership’s units are distributed through the Partnership or other selling
agents, including Man Investments Inc. (“MII”), an affiliate of the Advisor and
General Partner. MII is a registered broker-dealer and a member of the Financial
Industry Regulatory Authority, Inc. (“FINRA”).




On
January 28, 2008, the Partnership filed a registration statement with the
Securities and Exchange Commission to allow over 500 investors in the
Partnership.




On April
1, 2009, the Partnership added two new series: Class A Series 2 (“Class A-2”)
and Class B Series 2 units (“Class B-2”).  Except as described in
Footnote 4 below, Class A-2 and Class B-2 units are identical to class A and B
units, respectfully.


2.
            SIGNIFICANT
      ACCOUNTING POLICIES




The
Partnership prepares its financial statements in conformity with accounting
principles generally accepted in the United States of America. The following is
a summary of the significant accounting and reporting policies used in preparing
the financial statements.




Use of Estimates — The preparation of financial
statements in conformity with accounting principles generally accepted in the
United States of America requires the General Partner to make estimates and
assumptions that affect the reported amounts of assets and liabilities (and
disclosure of contingent assets and liabilities) at the date of the financial
statements and the reported amounts of revenues and expenses during the
reporting period. Actual results could differ from those estimates.




Investment in Man-AHL Diversified
Trading Company L.P. — The Partnership’s investment in the Trading
Company is valued at fair value at the Partnership’s proportionate interest in
the net assets of the Trading Company. Investment transactions are recorded on a
trade date basis. The performance of




8






the
Partnership is directly affected by the performance of the Trading Company.
Attached are the financial statements of the Trading Company, which are an
integral part of these financial statements.  Valuation of investments
held by the Trading Company is discussed in the notes to the Trading Company’s
financial statements.




The
Partnership can redeem any or all of its limited partnership interests in the
Trading Company at any month-end at the net asset value per unit of the Trading
Company. At June 30, 2009 and 2008, the Partnership owned 23,915 and 13,121
Class A units, respectively, of the Trading Company.  The Partnership
also owned 4,648 Class B units, 493 Class A-2 units and 209 Class B-2 units at
June 30, 2009. The Partnership’s aggregate ownership percentage of the Trading
Company (Class A, A-2, B and B-2 units) at June 30, 2009 and 2008, was 52.70%
and 32.11%, respectively.




The
Partnership segregates its investments into three levels based upon the inputs
used to derive the fair value.  “Level 1” investments use inputs from
unadjusted quoted prices from active markets.  “Level 2” investments
reflect inputs other than quoted prices, but use observable market
data.  “Level 3” investments are valued using mainly unobservable
inputs.  These unobservable inputs for “Level 3” investments reflect
the Partnership’s assumption about the assumptions market participants would use
in pricing the investments.  As of June 30, 2009, all of the
Partnership’s investments are “Level 3”.  See the notes to the
financial statements of the Trading Company L.P. for expanded SFAS 157
disclosures.




Cash and Cash Equivalents —
Cash and cash equivalents include cash and short-term interest bearing money
market instruments with original maturities of 90 days or less, held with
JPMorgan Chase, N.A.




Brokerage Commissions Expense
— Brokerage commission expense on futures and forward contracts traded in the
Trading Company is charged at institutional rates based on trading
volume.




Income Taxes — Income taxes
are not provided for by the Partnership because taxable income or loss of the
Partnership is includable in the income tax returns of the individual
partners.




Net Income (Loss) Per Unit —
Net income (loss) per unit of Class A, Class A-2, Class B or Class B-2
partnership interest is equal to the change in net asset value per unit of the
respective classes, from the beginning of the period to the end of the period.
Unit amounts are rounded to whole numbers for financial statement
presentation.




Subscriptions Received in
Advance — Subscriptions received in advance are comprised of cash
received prior to the statement of financial condition date for which units were
issued on the first day of the following month. Subscriptions received in
advance do not participate in the earnings of the Partnership until the related
units are issued.







3.
            LIMITED
      PARTNERSHIP AGREEMENT




The
General Partner and each limited partner share in the profits and losses of the
Partnership in proportion to the number of units or unit equivalents held by
each partner. However, no limited partner is liable for obligations of the
Partnership in excess of its capital subscription and net profits or losses, if
any.




The
Partnership’s units are continuously offered as of the first business day of
each month at net asset value, as defined in the Limited Partnership Agreement
(the “Agreement”). Limited partners may redeem any or all of their units as of
the end of any month at net asset value per unit on 10 days prior written notice
to the General Partner. The Partnership will be dissolved on December 31,
2037, or upon the occurrence of certain events, as specified in the
Agreement.




The
General Partner is required to make and maintain a general partner investment in
the Partnership in an aggregate amount equal to the lesser of 1.01 % of the net
aggregate capital subscriptions of all partners, or $500,000.




9


Distributions
(other than redemptions of units), if any, are made on a pro rata basis at the
sole discretion of the General Partner.




Under the
terms of the Agreement, the Partnership is liable for all costs associated with
executing its business strategy.  These costs include, but are not
limited to expenses associated with the execution of the Partnership’s
investments strategy, such as, brokerage commissions, management and incentive
fees and other operating expenses, such as legal, audit, and tax return
preparation fees.







4.
            EXPENSES




For all
classes of units, the Advisor earns a monthly management fee in an amount equal
to 0.1667% (2% annually) of the Partnership’s month-end net asset value, as
defined in the Agreement. With the exception of Series 2 of Class A and B, the
General Partner earns a monthly General Partner fee in an amount equal to
0.0833% (1% annually) of the Partnership’s month-end net asset value, as defined
in the Agreement. The General Partner fee is included in management fees in the
statements of operations.
  The
Advisor also earns a monthly incentive fee equal to 20% of any Net New
Appreciation, as defined in the Agreement, achieved by the Partnership. The
incentive fee is retained by the Advisor even if subsequent losses are incurred;
however, no subsequent incentive fees will be paid to the Advisor until any such
trading losses are recouped by the Partnership.
  The
Partnership pays a monthly servicing fee to the Placement Agent in an amount
equal to 0.1250% (1.5% annually) of the Partnership’s month-end net asset value,
as defined in the supplement to the Agreement, dated July 15,
2008.  For classes A-2 and B-2, the Partnership pays a monthly
servicing fee to the placement agent in an amount equal to 0.1042% (1.25%
annually) of the Partnership’s month-end net asset value, as defined in the
supplement to the Agreement, dated January 2, 2009.  For all classes
of units, MII serves as the placement agent for the Partnership.


5.
            DERIVATIVE
      FINANCIAL INSTRUMENTS




The
Partnership’s operating activities involve trading, indirectly through its
investment in the Trading Company, in derivative financial instruments that
involve varying degrees of market and credit risk. With respect to the
Partnership’s investment in the Trading Company, the Partnership has limited
liability, and, therefore, its maximum exposure to either market or credit loss
is limited to the carrying value of its investment in the Trading Company, as
set forth in the statements of financial condition.




The
Trading Company utilizes MF Global, Inc. (“MFG”), formerly known as Man
Financial Inc. (Man) and Credit Suisse to clear its futures trading
activity.  The Trading Company utilizes Royal Bank of Scotland (“RBS”)
and JPMorgan Chase to clear its forward trading activity.


6.
            FINANCIAL
      GUARANTEES




The
Partnership enters into administrative and other professional service contracts
that contain a variety of indemnifications. The Partnership’s maximum exposure
under these arrangements is not known; however, the Partnership has not had
prior claims or losses pursuant to these contracts and expects the risk of loss
to be remote.







7.
            RECENT
      ACCOUNTING PRONOUNCEMENTS




In June
2009, the FASB issued SFAS No. 168, “The FASB Accounting Standards
Codification and the Hierarchy of Generally Accepted Accounting Principles-a
replacement of FAS No. 162” (“SFAS




10




168”), which establishes the
FASB Accounting Standards Codification (the “Codification”) as the source of
authoritative U.S. generally accepted accounting principles recognized by the
FASB to be applied by nongovernmental entities. This statement is effective for
financial statements issued for interim and annual periods ending after
September 15, 2009. On the effective date of this Statement, the Codification
will supersede all then-existing non-SEC accounting and reporting standards. All
other non-grandfathered non-SEC accounting literature not included in the
Codification will become non-authoritative. The adoption of SFAS 168 will
require the Fund to adjust references to authoritative accounting literature in
the financial statements, but will not affect the Fund’s financial position or
results of operations.







8.
            SUBSEQUENT
      EVENTS




Effective
for interim and annual periods ending after June 15, 2009, the Partnership
adopted the provisions in Financial Accounting Standard No. 165 and has
evaluated subsequent events through August 14, 2009, the date the financial
statements were issued.














































11


Man-AHL
Diversified Trading Company L.P.


Financial
Statements





STATEMENTS
OF FINANCIAL CONDITION (a)


STATEMENTS
OF OPERATIONS (b)


STATEMENTS
OF CHANGES IN PARTNERS’ CAPITAL (c)


STATEMENTS
OF CASH FLOWS (c)


NOTES TO
THE FINANCIAL STATEMENTS (UNAUDITED)





(a)
            At
      June 30, 2009 (unaudited) and December 31,
2008


(b)
            For
      the three months ended June 30, 2009 and 2008 (unaudited) and for the six
      months endedJune
      30, 2009 and 2008 (unaudited)


(c)
            For
      the six months ended June 30, 2009 and 2008
  (unaudited)


















































12




MAN-AHL
      DIVERSIFIED TRADING COMPANY L.P.(A
      Delaware Limited Partnership)STATEMENTS
      OF FINANCIAL CONDITIONJune 30, 2009(unaudited)
                          
                          
                          December 31, 2008ASSETSEquity
      in commodity futures and forwardstrading
      accounts:Net
      unrealized trading gains on open futures contracts
                          
                          $
                          2,159,609
                          
                          
                          $
                          15,887,019Net
      unrealized trading gains on open forward contracts
                          
                          
                          -
                          
                          
                          
                          1,527,892Due
      from brokers
                          
                          
                          45,691,041
                          
                          
                          
                          25,700,72247,850,650
                          
                          
                          
                          43,115,633Cash
      and cash equivalents
                          
                          
                          480,767,830
                          
                          
                          
                          484,593,631Interest
      receivable
                          
                          
                          7,650
                          
                          
                          
                          90,491TOTAL
                          
                          $
                          528,626,130
                          
                          
                          $
                          527,799,755LIABILITIES
      AND PARTNERS’ CAPITALLIABILITIES
      —Redemptions
      payable
                          
                          $
                          12,442,855
                          
                          
                          $
                          24,783,667Net
      unrealized trading losses on open forward contracts
                          
                          
                          2,754,572
                          
                          
                          
                          -Total
      liabilities
                          
                          $
                          15,197,427
                          
                          
                          $
                          24,783,667PARTNERS’
      CAPITAL:Limited
      Partners (55,528 and 48,103 units outstanding atJune
      30, 2009 and December 31, 2008, respectively)
                          
                          
                          513,428,703
                          
                          
                          
                          503,016,088Total
      partners’ capital
                          
                          
                          513,428,703
                          
                          
                          
                          503,016,088TOTAL
                          
                          $
                          528,626,130
                          
                          
                          $
                          527,799,755NET
      ASSET VALUE PER OUTSTANDING UNIT OFPARTNERSHIP
      INTEREST
                          
                          $
                          9,246.38
                          
                          
                          $
                          10,457.01See
      notes to financial statements.






13




MAN-AHL
      DIVERSIFIED TRADING COMPANY L.P.(A
      Delaware Limited Partnership)STATEMENTS
      OF OPERATIONS (UNAUDITED)For
      the three
                          
                          
                          For
      the three
                          
                          
                          For
      the six
                          
                          
                          For
      the sixmonths
      ended
                          
                          
                          months
      ended
                          
                          
                          months
      ended
                          
                          
                          months
      endedJune 30, 2009
                          
                          
                          June 30, 2008
                          
                          
                          June 30, 2009
                          
                          
                          June 30, 2008NET
      INVESTMENT INCOME:Interest
      income
                          
                          $
                          192,901
                          
                          
                          $
                          1,921,985
                          
                          
                          $
                          485,381
                          
                          
                          $
                          3,974,202NET
      REALIZED AND UNREALIZEDGAINS
      (LOSSES) ON TRADINGACTIVITIES:Net
      realized trading gains (losses) onclosed
      contracts
                          
                          
                          (35,599,982
                          )
                          
                          
                          17,480,365
                          
                          
                          
                          (47,018,573
                          )
                          
                          
                          68,991,602Net
      change in unrealized tradinglosses
      on open contracts
                          
                          
                          4,610,399
                          
                          
                          
                          (299,587
                          )
                          
                          
                          (18,009,874
                          )
                          
                          
                          (3,457,651
                          )NET
      GAIN (LOSS) ON TRADINGACTIVITIES
                          
                          
                          (30,989,583
                          )
                          
                          
                          17,180,778
                          
                          
                          
                          (65,028,447
                          )
                          
                          
                          65,533,951NET
      INCOME (LOSS)
                          
                          $
                          (30,796,682
                          )
                          
                          $
                          19,102,763
                          
                          
                          $
                          (64,543,066
                          )
                          
                          $
                          69,508,153NET
      INCOME (LOSS) FOR A UNITOF
      PARTNERSHIP INTEREST
                          
                          $
                          (555.15
                          )
                          
                          $
                          463.27
                          
                          
                          $
                          (1,210.63
                          )
                          
                          $
                          1,821.34See
      notes to financial statements.






14




MAN-AHL
      DIVERSIFIED TRADING COMPANY L.P.(A
      Delaware Limited Partnership)STATEMENTS
      OF CHANGES IN PARTNERS’ CAPITAL (UNAUDITED)FOR
      THE SIX MONTHS ENDED JUNE 30, 2009 AND 2008Limited
                          
                          
                          GeneralPartners
                          
                          
                          Partner
                          
                          
                          TotalPARTNERS’
      CAPITAL — December 31, 2007
                          
                          $
                          260,209,821
                          
                          
                          $
                          -
                          
                          
                          $
                          260,209,821Issuance
      of 11,972 units of limitedpartnership
      interest
                          
                          
                          101,649,918
                          
                          
                          
                          -
                          
                          
                          
                          101,649,918Redemption
      of 6,310 units of limitedpartnership
      interest
                          
                          
                          (54,889,323
                          )
                          
                          
                          -
                          
                          
                          
                          (54,889,323
                          )Net
      income
                          
                          
                          69,508,153
                          
                          
                          
                          -
                          
                          
                          
                          69,508,153PARTNERS’
      CAPITAL — June 30, 2008
                          
                          $
                          376,478,569
                          
                          
                          $
                          -
                          
                          
                          $
                          376,478,569PARTNERS’
      CAPITAL — December 31, 2008
                          
                          $
                          503,016,088
                          
                          
                          $
                          -
                          
                          
                          $
                          503,016,088Issuance
      of 16,059 units of limitedpartnership
      interest
                          
                          
                          159,304,103
                          
                          
                          
                          -
                          
                          
                          
                          159,304,103Redemption
      of 8,634 units of limitedpartnership
      interest
                          
                          
                          (84,348,422
                          )
                          
                          
                          -
                          
                          
                          
                          (84,348,422
                          )Net
      loss
                          
                          
                          (64,543,066
                          )
                          
                          
                          -
                          
                          
                          
                          (64,543,066
                          )PARTNERS’
      CAPITAL — June 30, 2009
                          
                          $
                          513,428,703
                          
                          
                          $
                          -
                          
                          
                          $
                          513,428,703See
      notes to financial statements.






15




MAN-AHL
      DIVERSIFIED TRADING COMPANY L.P.(A
      Delaware Limited Partnership)STATEMENTS
      OF CASH FLOWS (UNAUDITED)For
      the six
                
                
                For
      the sixmonths
      ended
                
                
                months
      endedJune 30, 2009
                
                
                June 30, 2008CASH
      FLOWS FROM OPERATINGACTIVITIES:Net
      income (loss)
                
                $
                (64,543,066
                )
                
                $
                69,508,153Adjustments
      to reconcile net income (loss)to
      net cash provided by (used in)operating
      activities:Net
      change in unrealized tradinggains
      on open contracts
                
                
                18,009,874
                
                
                
                3,457,651Changes
      in assets and liabilities:Due
      from brokers
                
                
                (19,990,319
                )
                
                
                54,562,544Interest
      receivable
                
                
                82,841
                
                
                
                64,015Net
      cash provided by (used in)operating
      activities
                
                
                (66,440,670
                )
                
                
                127,592,363CASH
      FLOWS FROM FINANCINGACTIVITIES:Proceeds
      from subscriptions
                
                
                159,304,103
                
                
                
                101,649,918Payments
      on redemptions
                
                
                (96,689,234
                )
                
                
                (51,161,853
                )Net
      cash provided byfinancing
      activities
                
                
                62,614,869
                
                
                
                50,488,065NET
      INCREASE (DECREASE) IN CASHAND
      CASH EQUIVALENTS
                
                
                (3,825,801
                )
                
                
                178,080,428CASH
      AND CASH EQUIVALENTSBeginning
      of period
                
                
                484,593,631
                
                
                
                158,733,582CASH
      AND CASH EQUIVALENTSEnd
      of period
                
                $
                480,767,830
                
                
                $
                336,814,010See
      notes to financial statements.






16




Notes
to Financial Statements (unaudited)





The
accompanying unaudited financial statements, in the opinion of management,
include all adjustments (consisting only of normal recurring adjustments)
necessary for a fair presentation of Man-AHL Diversified Trading Company L.P.’s
(a Delaware Limited Partnership) (the “Partnership”) financial condition at June
30, 2009 and the results of its operations for the three months ended June 30,
2009 and 2008 and six months ended June 30, 2009 and 2008.  These
financial statements present the results of interim periods and do not include
all the disclosures normally provided in annual financial statements. It is
suggested that these financial statements be read in conjunction with the
audited financial statements and notes included in Man-AHL Diversified I L.P.’s
annual report on Form 10-K filed with the Securities and Exchange Commission on
March 31, 2009.  The December 31, 2008 information has been derived
from the audited financial statements as of December 31, 2008.







1.
            ORGANIZATION
      OF THE PARTNERSHIP




Man-AHL
Diversified Trading Company L.P. (a Delaware Limited Partnership) (the
“Partnership”) was organized in November 1997 under the Delaware Revised
Uniform Limited Partnership Act and commenced operations on April 3, 1998,
for the purpose of engaging in the speculative trading of futures and forward
contracts. Man Investments (USA) Corp. (the “General Partner”), a Delaware
corporation and a registered investment adviser under the Investment Advisers
Act of 1940, serves as the Partnership’s general partner. The General Partner is
a subsidiary of Man Group plc, a United Kingdom public limited company that is
listed on the London Stock Exchange. The General Partner oversees the operations
and management of the Partnership. The General Partner is registered with the
Commodity Futures Trading Commission (“CFTC”) as a commodity pool operator and
commodity trading adviser and is a member of the National Futures Association
(“NFA”).




The
Partnership was formed to serve as a trading vehicle for certain limited
partnerships sponsored by the General Partner in a “master-feeder” structure.
The limited partners, Man-AHL Diversified I L.P., Man-AHL Diversified II L.P.,
and Man-AHL Diversified L.P., are limited partnerships whose general partner is
the General Partner.




Man-AHL
(USA) Ltd. (the “Advisor”), a limited liability company incorporated in the
United Kingdom, acts as trading advisor to the Partnership. The Advisor is an
affiliate of the General Partner and a subsidiary of Man Group plc. The Advisor
is registered with the CFTC as a commodity pool operator and commodity trading
advisor, and is a member of the NFA, in addition to registration with the
Financial Services Authority in the United Kingdom.







2.
            SIGNIFICANT
      ACCOUNTING POLICIES





The
Partnership prepares its financial statements in conformity with accounting
principles generally accepted in the United States of America. The following is
a summary of the significant accounting and reporting policies used in preparing
the financial statements.





Use of Estimates — The
preparation of financial statements in conformity with accounting principles
generally accepted in the United States of America requires the General Partner
to make estimates and assumptions that affect the reported amounts of assets and
liabilities (and disclosure of contingent assets and liabilities) at the date of
the financial statements and the reported amounts of revenues and expenses
during the reporting period. Actual results could differ from those
estimates.




Due From Brokers — Due from
brokers consists of balances due from MF Global, Inc. (“MFG”), formerly known as
Man Financial Inc., Credit Suisse (“CS”), JPMorgan Chase Bank, N.A. (“JPM”) and
Royal Bank of Scotland (“RBS”). In general, the brokers pay the Partnership
interest monthly, based on agreed upon rates, on the Partnership’s average daily
balance.




17





MFG, CS,
JPM and RBS are registered with the CFTC as futures commission merchants and are
members of the NFA.




Amounts
due from brokers include cash held at brokers and cash posted as collateral.
Included in due from broker on the statements of assets and liabilities is
$11,591,040 of cash restricted as collateral held.




Derivative Contracts — In the
normal course of business, the Partnership enters into derivative contracts
(derivatives) for trading purposes. Derivatives include futures and forward
contracts. The Partnership records its derivative activities at fair value.
Futures contracts, which are traded on a national exchange, are valued at the
close price as of the valuation day, or if no sale occurred on such day, at the
close price on the most recent date on which a sale occurred.  Forward
contracts, which are not traded on a national exchange, are valued at fair value
using current market quotations provided by brokers.




The
Partnership segregates its investments into three levels based upon the inputs
used to derive the fair value.  “Level 1” investments use inputs from
unadjusted quoted prices from active markets.  “Level 2” investments
reflect inputs other than quoted prices, but use observable market
data.  “Level 3” investments are valued using unobservable
inputs.  These unobservable inputs for “Level 3” investments reflect
the Partnership’s assumption about the assumptions market participants would use
in pricing the investments.  As of June 30, 2009, the Partnership did
not have any positions in “Level 3”.




The
following is a summary of the inputs used in valuing the Partnership’s assets
and liabilities at fair value at June 30, 2009:





Fair
      Value MeasurmentsQuoted
                                        Prices
      inActive
                                        Markets
      for
                                      
                                      
                                      Significant
                                          Other
                                      
                                      
                                      Significant
                                          OtherFair
      Valueas of
                                      
                                      
                                      Identical
                                        Assets
                                      
                                      
                                      ObservableInputs
                                      
                                      
                                      UnobservableInputsDescription
                                      
                                      June
      30, 2009
                                      
                                      
                                      (Level
      1)
                                      
                                      
                                      (Level
      2)
                                      
                                      
                                      (Level
      3)Net
      unrealized trading gains on open futures contracts
                                      
                                      $
                                      2,159,609
                                      
                                      
                                      $
                                      2,159,609
                                      
                                      
                                      $
                                      -
                                      
                                      
                                      $
                                      -Net
      unrealized trading losses on open forward contracts
                                      
                                      $
                                      (2,754,572
                                      )
                                      
                                      $
                                      -
                                      
                                      
                                      $
                                      (2,754,572
                                      )
                                      
                                      
                                      -Total
                                      
                                      $
                                      (594,963
                                      )
                                      
                                      $
                                      2,159,609
                                      
                                      
                                      $
                                      (2,754,572
                                      )
                                      
                                      $
                                      -




Income Recognition — Realized
and unrealized trading gains and losses on futures and forward contracts, which
represent the difference between cost and selling price or fair value, are
recognized in the statements of operations. All trading activities are accounted
for on a trade-date basis. Interest income is recorded on an accrual
basis.




Foreign Currency Translation
— Assets, liabilities, gains, and losses denominated in foreign currencies are
translated at exchange rates at the date of valuation. The resulting net
realized and unrealized foreign exchange gains and losses are recorded in net
realized and unrealized gains (losses) on trading activities in the statements
of operations.




Cash and Cash Equivalents —
Cash and cash equivalents include cash and short-term interest bearing money
market instruments with original maturities of 90 days or less, held with
JPMorgan Chase, N.A.  As of June 30, 2009, the Partnership has no cash
equivalents.




Income Taxes — Income taxes
are not provided for by the Partnership because taxable income or loss of the
Partnership is includable in the income tax returns of the
partners.




18




Net Income (Loss) Per Unit —
Net income (loss) per unit of partnership interest is equal to the change in net
asset value per unit from the beginning of the period to the end of the period.
Unit amounts are rounded to whole numbers for financial statement
presentation.




3.
            ADVISORY
      AGREEMENT AND PARTNERSHIP AGREEMENT




The
Advisor is the sole trading advisor to the Partnership.




The
General Partner and limited partners share in the profits and losses of the
Partnership in proportion to the number of units or unit equivalents held by
each partner. However, no limited partner is liable for obligations of the
Partnership in excess of its capital contribution and net profits or losses, if
any. The General Partner owned no direct interest in the Partnership during the
six month periods ended June 30, 2009 and 2008.




Distributions
(other than redemption of units), if any, are made on a pro rata basis at the
sole discretion of the General Partner.




The
Partnership incurs no expenses. The limited partners are responsible for
expenses incurred in connection with the Partnership’s activities. These
expenses include, but are not limited to, all costs relating to trading
activity, such as brokerage commissions, management and incentive fees,
continuing offering expenses and legal, audit, and tax return preparation
fees.




Partner
contributions occur as of the first day of any month at the opening net asset
value.  Limited partners may redeem any or all of their units as of
the end of any month at net asset value per unit on 10 days prior written
notice to the General Partner. The General Partner may suspend redemptions of
units of the Partnership’s investments that are illiquid only if the
Partnership’s ability to withdraw capital from any investment is restricted. The
Partnership will be dissolved on December 31, 2037, or upon the occurrence
of certain events, as specified in the Limited Partnership Agreement (the
“Agreement”).




4.
            DERIVATIVE
      FINANCIAL INSTRUMENTS




The
Partnership trades derivative financial instruments that involve varying degrees
of market and credit risk. Market risks may arise from unfavorable changes in
interest rates, foreign exchange rates, or the fair values of the instruments
underlying the contracts. All contracts are stated at fair value, and changes in
those values are reflected in the change in net unrealized trading gains
(losses) on open contracts in the statements of operations.




Credit
risk arises from the potential inability of counterparties to perform in
accordance with the terms of the contract. The credit risk from counterparty
non-performance associated with these instruments is the net unrealized trading
gain, if any, included in the statements of financial condition. Forward
contracts are entered into on an arm’s-length basis with RBS.  In
applying Financial Accounting Standards Board (“FASB”) Interpretation No. 39,
“Offsetting of Amounts Related
to Certain Contracts” (“FIN No. 39”), the Partnership’s accounting policy
is such that open contracts with the same counterparty are netted at the account
level, in accordance with master netting arrangements in place with each party,
as applicable. Netting is effective across products and cash collateral when so
specified in the applicable netting agreement.




For
exchange-traded contracts, the clearing organization functions as the
counterparty of specific transactions and, therefore, bears the risk of delivery
to and from counterparties to specific positions, which mitigates the credit
risk of these instruments.  At June 30, 2009 and December 31, 2008,
estimated credit risk with regard to forward contracts was $0 and $1,527,892,
respectively.




The
Partnership trades in exchange-traded futures contracts on various underlying
commodities, foreign currencies, and financial instruments, as well as forward
contracts on foreign currencies.  Fair




19




values of
futures and forward contracts are reflected net by counterparty or clearing
broker in the statements of financial condition.




The
Partnership’s funds held by, and cleared through, MFG, CS, JPM and RBS are
required to be held in segregated accounts under rules of the CFTC. These funds
are used to meet minimum maintenance margin requirements for all of the
Partnership’s open futures positions as set by the exchange where each contract
is traded. These requirements are adjusted, as needed, due to daily fluctuations
in the values of the underlying positions. Certain positions may be liquidated,
if necessary, to satisfy resulting changes in margin requirements.




Effective
January 1, 2009, the Partnership has adopted the provisions of Statement of
Financial Accounting Standards No. 161, “Disclosures about Derivative
Instruments and Hedging Activities, an amendment of FASB Statement No.
133” (“SFAS No. 161”). SFAS No. 161 amends and expands the disclosure
requirements of SFAS No. 133 “Accounting for Derivative
Instruments and HedgingActivities”(“SFAS No. 133”) with the intent to
provide users of financial statements with an enhanced understanding of: (i) how
and why an entity uses derivative instruments; (ii) how derivative instruments
and related hedged items are accounted for under SFAS No. 133 and its related
interpretations; and (iii) how derivative instruments and related hedged items
affect an entity’s financial position, financial performance, and cash
flows.  Adoption of SFAS 161 impacted disclosures only and, had no
impact on the Partnership’s financial condition, results of operations or cash
flows.




The
investment objective of the Partnership is achieved by participation in the AHL
Diversified Program directed on behalf of the Partnership by Man-AHL (USA)
Limited.  The AHL Diversified Program is a futures and forward price
trend-following trading system, entirely quantitative in nature, and implements
trading positions on the basis of statistical analyses of past price
histories.  The Partnership is to deliver substantial capital growth
for commensurate levels of volatility over the medium term, independent of the
movement of the stock and bond markets, through the speculative trading,
directly and indirectly, of physical commodities, futures contracts, spot and
forward contracts, options on the foregoing, exchanges of futures for physical
transactions and other investments on domestic and international exchanges and
markets (including the interbank and OTC markets).  The AHL Diversified
Program trades globally in several market sectors, including, without
limitation, currencies, bonds, energies, stocks indices, interest rates, metals
and agricultural.





All the
strategies and systems of the AHL Diversified Program are designed to target
defined volatility levels rather than returns, and the investment process is
underpinned by computer-supported analytical instruments and disciplined
real-time risk and management information systems.  A proprietary risk
measurement method similar to the industry standard “value-at-risk” helps ensure
that the rule-based decisions that drive the investment process remain within
predefined risk parameters.  Margin-to-equity ratios are monitored
daily, and the level of exposure in each market is quantifiable at any time and
is adjusted in accordance with market volatility.  Market correlation
is closely monitored to prevent over-concentration of risk and ensure optimal
portfolio weightings.  Market liquidity is examined with the objective
of ensuring that the Partnership will be able to initiate and close out trades
as indicated by the AHL Diversified Program’s systems at market prices, while
brokerage selection and trade execution are continually monitored with the
objective of ensuring quality market access.





During
the quarter ended June 30, 2009, the Partnership traded 65,567 exchange traded
future contracts and settled 24,950 OTC forward contracts. During the six
month period ended June 30, 2009, the Partnership traded 117,481 exchange traded
future contracts and settled 35,994 OTC forward contracts.





20




The
following table presents the fair value of the Partnership’s derivative
instruments and statement of financial condition location.





Derivatives
      not designated
                                                                  as
      hedging instruments
                                                                  under
      SFAS 133
                                                                Asset
      Derivatives
                                                                
                                                                Liability
      DerivativesJune
      30, 2009
                                                                
                                                                June
      30, 2009Statement
      of Financial
                                                                  Condition
                                                                
                                                                Fair
      Value **
                                                                
                                                                Statement
      of Financial
                                                                  Condition
                                                                
                                                                Fair
      Value **Op`en
      forward contracts
                                                                Net
      unrealized trading gains on open forward contracts
                                                                
                                                                $
                                                                
                                                                4,953,912
                                                                
                                                                Net
      unrealized trading losses on open forward contracts
                                                                
                                                                $
                                                                (7,708,484
                                                                )Open
      futures contracts
                                                                Net
      unrealized trading gains on open futures contracts
                                                                
                                                                
                                                                
                                                                6,769,716
                                                                
                                                                Net
      unrealized trading losses on open futures contracts
                                                                
                                                                
                                                                (4,610,107
                                                                )Total
      Derivatives
                                                                
                                                                
                                                                $
                                                                
                                                                11,723,628
                                                                
                                                                
                                                                
                                                                $
                                                                (12,318,591
                                                                )




** Open
forward and future contracts are presented on the gross basis for SFAS 161
purposes. Net unrealized trading gains and losses are netted by counterparty in
the Statements of Financial Condition in accordance with FIN 39.





The
following table presents the impact of derivative instruments on the statements
of operations. The Partnership did not designate any derivatives as hedging
instruments for the three months ended June 30, 2009.





Derivatives not

                                                        designated 
      as
                                                      
                                                      
                                                      For
      the Three Months Ended
                                                        June
      30, 2009
                                                      
                                                      
                                                      For
      the Six Months Ended
                                                        June
      30, 2009hedging
      instruments
                                                        under
      SFAS 133
                                                      Location
      of loss recognized in Income on Derivatives
                                                      
                                                      Gain/(Loss)
      on Derivatives
                                                      
                                                      
                                                      (Loss)
      on DerivativesForward
      contracts
                                                      Net
      realized trading losses on closed contracts
                                                      
                                                      $
                                                      (14,089,833
                                                      )
                                                      
                                                      $
                                                      (16,008,759
                                                      )Net
      change in unrealized trading gains on open contracts
                                                      
                                                      
                                                      3,069,974
                                                      
                                                      
                                                      
                                                      (4,282,464
                                                      )Futures
      contracts
                                                      Net
      realized trading losses on closed contracts
                                                      
                                                      
                                                      (21,510,149
                                                      )
                                                      
                                                      
                                                      (31,009,814
                                                      )Net
      change in unrealized trading gains on open contracts
                                                      
                                                      
                                                      1,540,425
                                                      
                                                      
                                                      
                                                      (13,727,410
                                                      )Total
                                                      
                                                      
                                                      $
                                                      (30,989,583
                                                      )
                                                      
                                                      $
                                                      (65,028,447
                                                      )







5.
            FINANCIAL
      GUARANTEES




The
Partnership enters into administrative and other professional service contracts
that contain a variety of indemnifications. The Partnership’s maximum exposure
under these arrangements is not known; however, the Partnership has not had
prior claims or losses pursuant to these contracts and expects the risk of loss
to be remote.







6.
            RECENT
      ACCOUNTING PRONOUNCEMENTS




In June
2009, the FASB issued SFAS No. 168, “The FASB Accounting Standards
Codification and the Hierarchy of Generally Accepted Accounting Principles-a
replacement of FAS No. 162” (“SFAS 168”), which establishes the FASB
Accounting Standards Codification (the “Codification”) as the




21




source of
authoritative U.S. generally accepted accounting principles recognized by the
FASB to be applied by nongovernmental entities. This statement is effective for
financial statements issued for interim and annual periods ending after
September 15, 2009. On the effective date of this Statement, the Codification
will supersede all then-existing non-SEC accounting and reporting standards. All
other non-grandfathered non-SEC accounting literature not included in the
Codification will become non-authoritative. The adoption of SFAS 168 will
require the Fund to adjust references to authoritative accounting literature in
the financial statements, but will not affect the Fund’s financial position or
results of operations.







7.
            SUBSEQUENT
      EVENTS




Effective
for interim and annual periods ending after June 15, 2009, the Partnership
adopted the provisions in Financial Accounting Standard No. 165 and has
evaluated subsequent events through August 14, 2009, the date the financial
statements were issued.



































22


ITEM
      2.
            Management's
      Discussion and Analysis of Financial Condition and Results of
      Operations.




Introduction




Reference
is made to Item 1, “Financial Statements.”  The information contained
therein is essential to, and should be read in conjunction with, the following
analysis.




Operational
Overview




Man-AHL
Diversified I L.P. (the “Partnership”) is a speculative managed futures fund
which trades through its investment in Man-AHL Diversified Trading Company L.P.
(the “Trading Company”) pursuant to the AHL Diversified Program, directed on
behalf of the Partnership by Man-AHL (USA) Limited.  The AHL
Diversified Program is a futures and forward price trend-following trading
system, entirely quantitative in nature, and implements trading positions on the
basis of statistical analyses of past price histories.  The AHL
Diversified Program is proprietary and confidential, so that substantially the
only information that can be furnished regarding the Partnership’s results of
operations is contained in the performance record of its
trading.  Past performance is not necessarily indicative of its
futures results.  Man Investments (USA) Corp., the general partner of
the Partnership (the “General Partner”) does believe, however, that there are
certain market conditions, for example, markets with pronounced price trends, in
which the Partnership has a greater likelihood of being profitable than in other
market environments.




Capital
Resources and Liquidity




Units may
be offered for sale as of the beginning, and may be redeemed as of the end, of
each month.




The
Partnership raises additional capital only through the sale of Units and capital
is increased through trading profits (if any) and interest
income.  The Partnership does not engage in borrowing.  The
Partnership, not being an operating company, does not incur capital
expenditures.  It functions solely as a passive trading vehicle,
investing the substantial majority of its assets in the Trading
Company.  Its remaining capital resources are used only as assets
available to make further investments in the Trading Company and pay Partnership
level expenses.  Accordingly, the amount of capital raised for the
Partnership should not have a significant impact on its operations.




Partnership
assets not invested in the Trading Company are maintained in cash and cash
equivalents in bank accounts or accounts with the JPMorgan Chase Bank, N.A. (the
“Broker”) and are readily available to the Partnership.  The
Partnership may redeem any part or all of its limited partnership interest in
the Trading Company at any month-end at the net asset value per unit of the
Trading Company.  The Trading Company’s assets are generally held as
cash or cash equivalents which are used to margin futures and provide collateral
for forward contracts and other over-the-counter contract positions and are
withdrawn, as necessary, to pay redemptions (to the Partnership and other
investors in the Trading Company).  Other than potential
market-imposed limitations on liquidity, due, for example, to limited open
interest in certain futures markets or to daily price fluctuation limits, which
are inherent in the Trading Company’s futures trading, the Trading Company’s
assets are highly liquid and are expected to remain so.




There
have been no material changes with respect to the Partnership's critical
accounting policies, off-balance sheet arrangements or disclosure of contractual
obligations as reported in the Partnership's Form 10-K filed March 31,
2009.




23




Results
of Operations




Due to
the nature of the Partnership’s trading, the results of operations for the
interim period presented should not be considered indicative of the results that
may be expected for the entire year.




Periods Ended June 30,
2009:




30-Jun -09
                31-Mar -09Ending
      Equity
                $270,592,541
                $232,322,608




Three
months ended June 30, 2009:




Net
assets increased $38,269,933 for the three months ended June 30,
2009.  This increase was attributable to subscriptions in the amount
of $72,966,664, redemptions in the amount of $15,608,783 and a net loss from
operations of $19,087,948.




Management
Fees of $1,976,382, brokerage commissions of $163,458 and servicing fees of
$990,802 were paid or accrued, and interest of $98,540 was earned or accrued on
the Partnership’s cash and cash equivalent investments, for the three months
ended June 30, 2009.




The
Partnership’s other expenses paid or accrued for the three months ended June 30,
2009 were $99,333.




Six
months ended June 30, 2009:




Net
assets increased $51,350,781 for the six months ended June 30,
2009.  This increase was attributable to subscriptions in the amount
of $118,078,449, redemptions in the amount of $29,211,508 and a net loss from
operations of $37,516,160.




Management
Fees of $3,714,397, brokerage commissions of $290,623 and servicing fees of
$1,859,809 were paid or accrued, and interest of $230,367 was earned or accrued
on the Partnership’s cash and cash equivalent investments, for the six months
ended June 30, 2009.




The
Partnership’s other expenses paid or accrued for the six months ended June 30,
2009 were $270,287.




Three
months ended June 30, 2009:




Agriculture
produced significant losses during the quarter, primarily driven by cotton,
wheat, coffee and cocoa positions. Cotton reached a six month high in early May,
although the AHL Diversified Program did not lock-in any profits due to volatile
trading. Short positions in wheat for April and May resulted in losses, as
prices rose. Losses were partially recovered in late June as short positions
profited from declining prices. Switching in mid-May to a long position in
coffee proved profitable in the short term, as wholesale coffee prices rose due
to continued demand despite the economic downturn. However, all gains were
reversed as prices fell sharply in June. Cocoa prices were highly volatile again
this quarter, as market sentiment over long term demand whipsawed, preventing
any profits from emerging. Sugar produced the greatest return as long positions
gained from a sustained rally.




The bond
sector experienced a loss over the quarter, dragged particularly by April’s
negative performance. The AHL Diversified Program’s long positions in US and
European government bonds proved particularly damaging to performance after
prices generally fell as risk appetite rose.




Renewed
concerns over a dramatic increase in US government bond issuance over the coming
months weighed heavily on US Treasuries. Prices fell further after a report on
home prices supported the view that the US housing market was stabilizing. In
Europe, bond prices slumped after the European Central Bank cut rates by a
smaller-than-expected amount. Elsewhere, long positions in UK Gilts also proved




24




damaging
over April and May as prices fell amid increasing alarm over UK’s rising debt
levels and fears that it could lose its triple A credit status.




Elsewhere,
long positions in Japanese government bonds were impacted by significant
fluctuations in May price movements.  A switch to short positions in
early June also proved unfavorable as prices rallied strongly throughout June.
Poor economic data, which suggested a slow economic recovery, was the main
driver of demand for the safe haven asset.  Profits generated from
exposure to Australian bonds over May and June managed to trim losses. As
Australian bond prices trended lower, the AHL Diversified Program’s short
positions benefited.




Currency
market trading incurred a loss for the quarter as a large degree of choppy
movements negatively impacted performance and offset gains
elsewhere.




At the
beginning of the period, world equity markets had enjoyed a month of strong
rising markets as investors responded to an improvement in news flow by
increasing risk levels. This rally in riskier assets continued in April and May
as signs of life in the banking system grew larger and China’s huge stimulus
plan began to filter through to official statistics. The latter played a key
role in the advance of commodity-linked currencies such as AUD, ZAR, BRL and NZD
in which the AHL Diversified Program held long positions against
USD.  All contributed strongly to returns over the period, although
the month of June was less beneficial than the previous two, as trends eased to
trade largely within a band.




For many
currencies, volatility in June was merely a continuation of choppy movements
experienced in the previous two months. For currency pairs, EUR/GBP and JPY/USD,
the quarter was significantly volatile with little observable trends developing.
This led to a significant fluctuation of positions which ultimately caused
losses for the AHL Diversified Program. The same was apparent with trading in
EUR/CHF although losses here were extended further due to a sharp snapback in
late June. Finally, the largest loss to the AHL Diversified Program came from
short positions in GBP/USD as the British pound advanced on the back of the rise
in risk appetite seen over April and May. In June, the currency traded within a
band with no notable trend, negatively impacting returns again.




The
energy sector produced the largest contribution to overall returns during the
quarter. Switching in early May to a long position in Crude Oil proved
profitable as it rallied to an eight month high of over USD 73 per barrel in
June. However, profits tailed off slightly toward the end of the month on news
of weaker-than-expected US consumer confidence. Gains also came from long
positions in Gasoline which closely followed the performance of
crude.  Natural gas detracted from profits as prices significantly
fluctuated due to conflicting economic data and concerns over a “supply crunch”
after Gazprom announced investment cuts and production delays.




Interest
rate trading was the principal source of losses for the quarter. Primarily long
positions in Eurodollar, Euribor and Short Sterling were responsible for the
losses as the previously profitable trend reversed in the second half of May and
in early June. Eurodollar prices plummeted over the period as positive economic
data, better than expected US unemployment figures being the main trigger,
sparked speculation of a rise in the US interest rates and a significant
increase in LIBOR rates towards the back end of the year. However, losses were
limited by gains secured in May especially from long positions in Eurodollar,
Euribor and Short Sterling.




Metals
positions suffered losses over the quarter. Base metals produced the worst
return with short positions in Nickel, Aluminum and Copper losing heavily as
these commodities climbed on positive manufacturing surveys in the US, Europe
and China and a weak US dollar. Long positions in the precious metals all
incurred small losses as prices fell sharply mid-way through June. Long
positions in Gold made steady profits during May, but again were quickly
reversed in June as the dollar strengthened.




Trading
in stock indices for the quarter finished negative despite accumulating gains in
April. Highly volatile markets since mid May meant the AHL Diversified Program
could not benefit from any sustained trends and duly surrendered all earlier
profits. The biggest losses were from exposure to the S&P 500.




25




Despite
the index having its best quarter since 1998, choppy trading meant the AHL
Diversified Program was unable to lock-in these gains. Other detractors came
from European markets with the Euro-Stoxx and Dax Index also lacking any
consistent trends. Long positions in the Hang Seng generated profits for the
quarter as Asian stocks surged upwards encouraged by signs of a global economic
recovery.




Three
months ended March 31, 2009:




Equity
markets continued on their downward trend in early 2009, before rallying
strongly in March.  Concerns over the severity of the worldwide
recession and lingering fears of bank nationalization drove equity values lower
in January and February. However, optimism returned to the market in March as
economic data improved and market commentators started to talk of a market
bottom being reached.




Amid this
environment, the AHL Diversified Program failed to build on its strong
performance from last quarter. Numerous long standing trends, from which the AHL
Diversified Program had profited in the past, became volatile or reversed
direction. This was the case for the majority of sectors, but currency and bond
markets in particular. Currency trading posted a loss over the quarter, with the
majority of losses coming in the last three weeks of March. Long Japanese yen
positions against the US dollar proved to be the largest detractor to
performance. Demand for the yen fell over the period as its appeal as a “safe
haven” asset came under threat. Poor export data and GDP figures painted a bleak
picture of the Japanese economy, while an uptick in risk appetite also reduced
demand for the yen. Within bond markets, primarily long positions in almost all
markets (US Treasuries and Japanese bond position in particular) were
responsible for losses as previously profitable trends became volatile and
choppy, with many positions impacted by a whipsawing in prices.




On the
positive side, exposure to equity and short-term interest rate markets posted
gains. A number of short equity positions capitalized on the slide in equity
values around the world, with short S&P 500 contracts providing the greatest
gains. On the short-term interest rate market side, long Euribor positions were
solely responsible for the positive returns seen within the sector.




The
agriculturals sector had mixed performance after small gains from wheat
positions were offset by slight losses from exposure to soymeal, soybeans and
corn. Short positions in wheat posted gains as prices continued to edge lower
due to demand concerns fuelled by the weakening economy. However, short
positions in soy and corn proved detrimental, especially in March, after prices
rose as Argentine farmers halted grain sales after the government rejected
demands to cut a 35% export tariff on soya.




Trading
in government bond markets posted a loss over the quarter. Primarily long
positions in almost all markets were responsible for the losses as previously
profitable trends became volatile and choppy, with many positions impacted by a
whipsawing in prices. Falling equity prices in January and February drove more
investors into bond markets. However, March saw a large rally in equities as
risk appetite improved, removing some demand for government
securities.




Currency
trading posted a loss over the quarter, with the majority of losses coming in
the last three weeks of March. Long Japanese yen positions against the US dollar
proved to be the largest detractor to performance. Demand for the yen fell over
the period. Short British pound positions versus the US dollar posted losses,
mainly due to volatility in this currency pair as the FX rate finished the
quarter relatively unchanged. The Swiss National Bank’s (SNB) decision to
intervene and devalue its currency produced negative performance for the AHL
Diversified Program’s long positions in the Swiss franc against the US dollar.
The SNB narrowed its target interest rate range, sold francs and bought bonds in
an attempt to provide stimulus to the countries export-driven economy and to
avoid deflation. Short Euro versus US dollar positions also weighed on
performance, particularly over the latter half of the quarter. The US currency
weakened as the Federal Reserve announced it was set to implement a quantitative
approach to monetary policy. The Fed stated it would buy $300bn of long-term US
Treasuries in an effort to boost market liquidity, surprising most
investors.




26




Energy
trading had an overall negative quarter as the previous year’s trend in the oil
market came to an end. The AHL Diversified Program struggled with whipsawing
trends in oil markets as prices became largely range bound as market forces in
both directions bought against each other. Global recession pushed oil prices
down while OPEC agreed to cut production and some positive economic data helped
rally commodities. Losses were improved by gains in short natural gas
trades.




Interest
rate trading posted gains for the quarter. Long Euribor positions were
responsible for almost all of the sector’s positive performance. Fears of
deflation, expectations of interest rates cuts and actual ECB moves in the
Eurozone area boosted prices throughout the period. Holding back further gains
were losses from Eurodollar positions held in February.




Trading
in base metals made a slight loss over the period. Short positions in copper
were the largest detractor from performance as the commodity experienced a rally
towards the end of the period amidst improving US economic data and a more
optimistic outlook for the Chinese economy. Short positions in aluminum proved
to be the best performer as prices declined sharply over January as the outlook
for future demand deteriorated and stock levels increased, pushing prices lower.
Trading in precious metals posted a loss over the quarter. Short positions in
silver proved to be misplaced as prices rose during the first of the period on
safe haven buying. Long gold trades benefited from this safe haven buying over
the first half of the period. However, prices failed to break through the all
important $1000 mark, falling back quickly and becoming largely range bound,
leading to losses over the second half of the quarter.




Periods Ended June 30,
2008:





30-Jun-08
                  31-Mar -08Ending
      Equity
                  $120,905,168
                  $89,361,244




Three
months ended June 30, 2008:




Net
assets increased $31,543,924 for the three months ended June 30,
2008.  This increase was attributable to subscriptions in the amount
of $33,573,732, redemptions in the amount of $5,802,819 and a net gain from
operations of $3,773,011.




Management
Fees of $820,725, Incentive Fees of $943,253 and brokerage commissions of
$228,214 were paid or accrued, and interest of $574,809 was earned or accrued on
the Partnership’s cash and cash equivalent investments, for the three months
ended June 30, 2008.




The
Partnership’s other expenses paid or accrued for the three months ended June 30,
2008 were $90,382.




Six
months ended June 30, 2008:





Net
assets increased $61,349,778 for the six months ended June 30,
2008.  This amount represents subscriptions in the amount of
$56,130,636, redemptions in the amount of $7,651,461 and a net gain from
operations of $12,870,603.




Management
Fees of $1,416,838, Incentive Fees of $3,211,277 and brokerage commissions of
$624,814 were paid or accrued, and interest of $1,088,781 was earned or accrued
on the Partnership’s cash and cash equivalent investments, for the six months
ended June 30, 2008.




The
Partnership’s other expenses paid or accrued for the six months ended June 30,
2008 were $124,695.




Three
months ended June 30, 2008:




Trading
in oil and gas markets proved particularly profitable over the period, where
long positions in crude oil and natural gas drove gains. Crude oil surged to new
highs during the period and natural gas prices rose sharply amid increased
demand from the power sector.




27





Long
crude oil positions registered strong gains as West Texas Intermediate (“WTI”)
rose 11.7% in April. A record high of US $119.70 per barrel was reached on April
25, as a weakening US dollar, unexpected falls in US inventories and production
difficulties drove prices higher. Long positions in products derived from crude
oil, such as RBOB gasoline, heating oil and gas oil, also made gains as prices
rose sharply.  WTI sustained its rise in May. A new closing high above
US $132 per barrel was reached amid worries that demand would outstrip supply
within the next few years and on the back of robust demand from China ahead of
the Olympics. Meanwhile, OPEC continued to insist that there was no shortage of
supply in the market and that elevated prices were a consequence of US dollar
weakness and investor speculation. WTI hit fresh highs again in June as
geopolitical tensions and concerns about disruptions to output in Nigeria
intensified, overshadowing Saudi Arabia's pledge to provide more crude
supplies.





Increasing
inflationary pressures and changing interest rate expectations proved beneficial
for bond and interest rate trading during the period as short positions in
Eurobonds and Euribor contributed to performance. Prices fell in June on
heightened speculation that the European Central Bank would lift interest rates
after eurozone inflation continued to rise. Profits were slightly offset,
however, by long positions in Asian equities and various equity indices as
markets came under pressure on fears over stagflation and falling confidence in
the financial and housing sectors.





The
period highlighted the increasingly difficult task facing the world's central
banks. The need to balance the risks to growth and the risks of accelerating
inflation saw a continued divergence in monetary policy over the
month.  In April, the Bank of England and Federal Reserve took action
to protect growth, both lowering interest rates by 0.25%, while the European
Central Bank focused on controlling inflation and left base rates unchanged at
4%.  Both the Bank of England and European Central Bank left interest
rates unchanged over the months of May and June.





In
currency markets, the US dollar regained some ground early in the period as
investors speculated that the latest decrease in US interest rates may mark the
end of the current loosening cycle.  The general improvement in
sentiment witnessed during April gave strength to the US dollar, which rallied
against the euro and Japanese yen towards the end of April, negatively affecting
our currency positions.  May and June witnessed US dollar weakness and
investor speculation.  In May, the Australian dollar hit a 24-year
high against the US dollar on the back of surging commodity prices and
disappointing US consumer confidence figures, which resulted in gains from long
Australian dollar positions.





Equity
markets began to recover in April from the heavy declines they registered in the
first quarter with the S&P 500, FTSE 100 and Nikkei 225 ending up over 4%,
6% and 10%, respectively.  Global equity markets continued to trend
higher in May as encouraging economic data releases in the US bolstered investor
sentiment and dampened talks of a recession.  Global equities suffered
a sharp sell-off in June, however, with the financial sector driving losses,
after persistent speculation that further sub-prime related writedowns were
imminent. The FTSE 100 and S&P 500 lost around 7% and 9%, respectively,
while the MSCI Asia Pacific fell 8.8%. The slide in equities and gains in
commodities increased gold's appeal, the precious metal rose 4.3% over the month
June.





Three
months ended March 31, 2008:




Equity
markets suffered heavy losses during the quarter as concerns over the health of
the financial system intensified and the outlook for the US economy
deteriorated.  January saw the largest declines with a number of
European and Asian indices registering double-digit monthly losses. Conditions
improved in February and March but equities continued to trend lower and markets
remained highly volatile.  The sharp sell-off in equity markets came
despite the Federal Reserve slashing its target funds rate from 4.25% to 2.25%
and central banks throughout the world injecting additional funds into money
markets to increase liquidity.  The Federal Reserve’s decision to cut
rates aggressively put further downward pressure on the dollar. The US currency
slumped to lifetime lows against the euro and Swiss franc and sank to a
multi-year low against the Japanese yen.  The weakness of the US
dollar sent




28




commodity
prices sharply higher. Oil rose to a series of lifetime highs, spending most of
the second half of the quarter above US $100 per barrel, while gold, base metal
and agricultural prices also climbed to record highs.




Trading
within agricultural markets made gains across the majority of contracts, with
corn trading providing the largest contribution. Soy-based products rose to
record highs during February on speculation that increased Chinese demand would
cut into US inventories, although March saw a retraction in prices, paring
earlier gains from long positions. Prices in soybean oil declined as Chinese
importers surprisingly cancelled an order and US farmers stated that a greater
proportion of land would be allocated to soy products in the
near-term.




Bond
trading accrued profits as Japanese bonds and US Treasuries led the way.
Disappointing US economic data saw investors switching out of riskier asset
classes and into government paper; sending the 2-year US Treasury yield from
3.05% on December 31, 2007 to 1.34% by mid-March. Long positions in Japanese
bonds also proved beneficial on increased speculation that the Bank of Japan
would cut interest rates to boost economic growth. However, gains were slightly
offset by short positions in Australian bonds as investors became concerned over
the impact of the credit crunch on economic growth.




Currency
trading contributed excellently during the period. The quarter saw the US dollar
continue to weaken against most major currencies due to ongoing concerns
regarding the credit crisis and the US housing market. As a result, long
positions in various currencies, in particular the Swiss franc, against the US
dollar proved highly beneficial. March witnessed the euro hitting a record high
of US $1.5846, as the European Central Bank (“ECB”) showed no indication of
cutting interest rates in the near future.




Energy
delivered a solid profit for the quarter as a weakening US dollar and increased
demand supported price rises. Long positions in crude oil were beneficial
despite the commodity sliding below US $90 at the beginning of the period.
However, concerns that OPEC may cut production levels and a disruption to oil
production in Nigeria sent prices higher, closing at a record high of US $110.33
per barrel on March 13. Distillate products such as gas oil and heating oil
followed the upward trend of crude, accruing strong profits via our long
positions.




Precious
metals trading made a solid profit as long positions in gold, silver and
platinum made gains.  Gold rocketed upwards during the start of the
period, eventually climbing above the US $1000 mark in mid-March. Elevated
global inflation, a deteriorating US economy and a weak US dollar all supported
the rise in gold, silver and platinum. In the base metals component, positive
trading in copper offset losses from aluminum.




Trading
in short-term interest rates posted a firm gain over the first quarter despite
market volatility.  Long positions in Eurodollar and Euribor contracts
posted the largest part of gains as investors bet on rate reductions in the US
and Europe as turmoil swept through global markets. However, these earlier gains
were reduced as hawkish rhetoric from the ECB indicated that interest rates for
the eurozone would remain stable in the near-term.




Stock
market trading posted a gain over the quarter, with short positions in the
Nikkei, TOPIX and S&P 500 proving particularly fruitful. Serious concerns
over the US economy prompted a large scale investor switch out of equities, with
rapidly falling Asian markets reversing some of the gains accrued in 2007. Short
exposure to European markets such as the Euro Stoxx, CAC40 and Dax also
contributed to gains. However, some profits were reversed as the Federal Reserve
intervened to calm markets with a 75bps federal funds rate cut, sending indices
higher at the end of March.




ITEM
      3.
            Quantitative
      and Qualitative Disclosures About Market
Risk.




Not
required.




29


ITEM
      4T.
              Controls
      and Procedures.


The
General Partner, with the participation of the General Partner's Chief Executive
Officer and Chief Financial Officer, has evaluated the effectiveness of the
design and operation of the Partnership’s disclosure controls and procedures as
of the end of the fiscal quarter ended June 30, 2009.  Based on such
evaluation, the Partnership’s Chief Executive Officer and Chief Financial
Officer have concluded that the Partnership’s disclosure controls and procedures
were effective as of the fiscal quarter ended June 30, 2009.





Changes in Internal Control
over Financial Reporting





There
were no changes in the Partnership’s internal control over financial reporting
during the quarter ended June 30, 2009 that have materially affected, or are
reasonably likely to  materially affect, our internal control over
financial reporting.




PART II - OTHER
INFORMATION




Item
      1.
            Legal
      Proceedings.




None.




Item
      1A.
            Risk
      Factors.




Not
required.




Item
      2.
            Unregistered
      Sales of Equity Securities and Use of
Proceeds.




(a)           Pursuant
to the Partnership’s Limited Partnership Agreement, the Partnership may sell
Units of Limited Partnership Interests (“Units”) as of the last business day of
any calendar month or at such other times as the General Partner may determine.
On April 30, 2009, May 31, 2009 and June 30, 2009, the Partnership sold Class A
Units, exclusive of non-cash transfers, to existing and new Limited Partners in
the amount of  $15,398,190.75, $17,409,607.50 and $17,679,449.00,respectively.  On
April 30, 2009, May 31, 2009 and June 30, 2009, the Partnership sold Class A-2
Units, exclusive of non-cash transfers, to existing and new Limited Partners in
the amount of  $686,000.00, $2,104,000.00 and $1,967,000.00,respectively.  On
April 30, 2009, May 31, 2009 and June 30, 2009, the Partnership sold Class B
Units, exclusive of non-cash transfers, to existing and new Limited Partners in
the amount of $4,215,181.00, $3,360,833.00 and $8,056,403.00,respectively.  On
April 30, 2009, May 31, 2009 and June 30, 2009, the Partnership sold Class B-2
Units, exclusive of non-cash transfers, to existing and new Limited Partners in
the amount of $1,066,000.00, $382,000.00 and $642,000.00,respectively.  There
were no underwriting discounts or commissions in connection with the sales of
the Units described above.




(b)           Not
applicable.




(c)           Pursuant
to the Partnership’s Limited Partnership Agreement, a Limited Partner may redeem
some or all of its Units as of the last business day of each calendar month at
the then current month-end Net Asset Value.  The redemption of Units
has no impact on the value of Units that remain outstanding, and Units are not
reissued once redeemed.  The following table summarizes the amount of
Units redeemed, exclusive of non-cash transfers, during the three months ended
June 30, 2009:




Class A Units
                                                      
                                                      Class A-2 Units
                                                      
                                                      Class B Units
                                                      
                                                      Class B-2 UnitsDate of Redemption:
                                                      
                                                      Amount Redeemed:
                                                      
                                                      Amount Redeemed:
                                                      
                                                      Amount Redeemed:
                                                      
                                                      Amount Redeemed:June
      30, 2009
                                                      
                                                      $7,784,318.97
                                                      
                                                      $0.00
                                                      
                                                      $704,782.87
                                                      
                                                      $0.00May
      31, 2009
                                                      
                                                      $3,456,129.06
                                                      
                                                      $0.00
                                                      
                                                      $168,400.66
                                                      
                                                      $0.00April
      30, 2009
                                                      
                                                      $3,350,101.99
                                                      
                                                      $0.00
                                                      
                                                      $94,784.35
                                                      
                                                      $0.00TOTAL
                                                      
                                                      $14,590,550.02
                                                      
                                                      $0.00
                                                      
                                                      $967,967.88
                                                      
                                                      $0.00






30




Item
      3.
            Defaults
      upon Senior Securities.




None.




Item
      4.
            Submissions
      of Matters to a Vote of Security
Holders.




None.




Item
      5.
            Other
      Information.




None




Item
      6.
            Exhibits.




The
following exhibits are included herewith:




Designation                      Description




31.1                           Rule
13a-14(a)/15d-14(a) Certification of Principal Executive Officer




31.2                           Rule
13a-14(a)/15d-14(a) Certification of Principal Financial Officer




32.1                           Section
1350 Certification of Principal Executive Officer




32.2                           Section
1350 Certification of Principal Financial Officer




The
following exhibit is incorporated by reference herein from the exhibit of the
same description and number filed on March 31, 2009 with the Partnership's
Annual Report on Form 10-K (Reg. No. 000-53043).




4.2
            Fifth
      Amended Limited Partnership Agreement of Man-AHL Diversified I
      L.P.




The
following exhibits are incorporated by reference herein from the exhibits of the
same description and number filed on January 28, 2008 with the Partnership's
Registration Statement on Form 10 (Reg. No. 000-53043).




3.1
            Certificate
      of Limited Partnership of Man-AHL Diversified I
  L.P.




10.1
            Form
      of Customer Agreement between E D & F Man International Inc. and
      Man-AHL Diversified Trading Company
L.P.




10.2
            Form
      of Trading Advisor Agreement between Man-AHL Diversified I L.P., Man
      Investments (USA) Corp. and Man-AHL (USA)
  Limited.




10.3
            Form
      of Selling Agreement between Man Investments (USA) Corp. and Man
      Investments Inc.






31






SIGNATURES




Pursuant
to the requirements of the Securities Exchange Act of 1934, the registrant has
duly caused this report to be signed on its behalf by the undersigned thereunto
duly authorized on August 14, 2009.




Man-AHL
      Diversified I L.P.
                                      (Registrant)By:
      Man Investments (USA) Corp.
                                      General
      PartnerBy:
      /s/
                                    Andrew
      StewartPresident
      and Chief Executive Officer(Principal
      Executive Officer)By:
      /s/
                                    Alicia
      Borst DerrahVice
      President, Chief Financial Officer and Secretary(Principal
      Financial and Chief Accounting Officer)






























32


EXHIBIT
INDEX




Exhibit Number
                Description of Document31.1
                Rule
      13a-14(a)/15d-14(a) Certification of Principal Executive
      Officer31.2
                Rule
      13a-14(a)/15d-14(a) Certification of Principal Financial
      Officer32.1
                Section
      1350 Certification of Principal Executive Officer32.2
                Section
      1350 Certification of Principal Financial
  Officer








E-1